There are known gas fuel distributors for a cooking appliance of the type mentioned above, such as that disclosed in WO 97/21960, which comprises various taps integrated in a distribution pipe, distanced from each other, and assembled with means for the airtight closure of the insertion holes on the tap body in the pipe.
Each of the gas taps disclosed therein includes a body portion comprising a fixed generally hollow frusto-conical casing positioned within the distribution pipe that has an inlet orifice for the inlet of gas from the distribution pipe. The gas tap also include a frusto-conical rotary plug member located within the casing having both a major orifice and a minor orifice. The plug member is rotatable by means of a control key such that the major and minor orifices of the plug member can be moved into and/or out of varying degrees of alignment with the inlet orifice of the casing to regulate or control the volume of gas flow through an outlet port of the tap. The major orifice is for variation of the gas flow from low to high flame in an associated burner and the minor orifice is for achieving a very low ‘simmer’ flame level. This device for gas distribution presents a problem in that the casing and the rotary plug member have substantially circular passage openings that cannot regulate an intermediate flow “Qgra” proportional to the angular path of the conical member. In addition, the distribution pipe of this known device for gas distribution has two flat opposing walls for the insertion and exit of the tap body, as a result of which the airtight closure of the coupling with the flat walls of the pipe is simple.